U.S. patent application number 11/852888 was filed with the patent office on 2008-08-14 for electronic component module and method for manufacturing the same.
This patent application is currently assigned to KYOCERA CORPORATION. Invention is credited to Tsutomu ADACHI, Hidefumi HATANAKA, Miho IMASHIOYA, Tomohiko TANIGUCHI, Youichi YOKOTE.
Application Number | 20080192443 11/852888 |
Document ID | / |
Family ID | 36953441 |
Filed Date | 2008-08-14 |
United States Patent
Application |
20080192443 |
Kind Code |
A1 |
HATANAKA; Hidefumi ; et
al. |
August 14, 2008 |
Electronic Component Module and Method for Manufacturing the
Same
Abstract
An electronic component module comprises a circuit board having
a cavity in one principal surface thereof. The electronic component
module also comprises a first semiconductor device accommodated
within the cavity and a second semiconductor device disposed on the
one principal surface of the circuit board so as to cover the first
semiconductor device in plan view. The electronic component module
further comprises a resin material disposed to cover at least a
side surface of the second semiconductor device.
Inventors: |
HATANAKA; Hidefumi;
(Kirishima, JP) ; ADACHI; Tsutomu; (Kirishima,
JP) ; YOKOTE; Youichi; (Kirishima, JP) ;
IMASHIOYA; Miho; (Kirishima, JP) ; TANIGUCHI;
Tomohiko; (Higashiomi, JP) |
Correspondence
Address: |
HOGAN & HARTSON L.L.P.
1999 AVENUE OF THE STARS, SUITE 1400
LOS ANGELES
CA
90067
US
|
Assignee: |
KYOCERA CORPORATION
Kyoto-shi
JP
KYOCERA KINSEKI CORPORATION
Tokyo
JP
|
Family ID: |
36953441 |
Appl. No.: |
11/852888 |
Filed: |
September 10, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2006/304736 |
Mar 10, 2006 |
|
|
|
11852888 |
|
|
|
|
Current U.S.
Class: |
361/728 ;
257/E25.023; 29/834 |
Current CPC
Class: |
H01L 2924/00014
20130101; H01L 2924/01006 20130101; H05K 1/0218 20130101; H05K
2201/10674 20130101; H01L 2924/01029 20130101; H01L 2924/01042
20130101; H05K 3/4697 20130101; H01L 2224/16225 20130101; H05K
2201/09845 20130101; H01L 2924/1517 20130101; H01L 2224/97
20130101; H05K 3/4611 20130101; H01L 25/105 20130101; H01L
2224/05568 20130101; H01L 24/97 20130101; H01L 2924/01047 20130101;
H01L 2924/00014 20130101; H01L 2224/45099 20130101; H01L 2224/45015
20130101; H01L 2224/81 20130101; H01L 2224/0555 20130101; H01L
2224/0556 20130101; H01L 2924/00012 20130101; H01L 2224/05599
20130101; H01L 2924/207 20130101; H01L 25/165 20130101; H01L
2924/01013 20130101; H01L 2924/10329 20130101; Y10T 29/49133
20150115; H01L 2924/00014 20130101; H05K 1/183 20130101; H05K
2201/10515 20130101; H05K 2201/10689 20130101; H01L 24/49 20130101;
H01L 2924/00014 20130101; H01L 2924/181 20130101; H01L 2224/49109
20130101; H05K 3/0052 20130101; H01L 2924/01082 20130101; H01L
2924/00014 20130101; H01L 2924/00014 20130101; H01L 2924/19041
20130101; H05K 3/284 20130101; H01L 25/50 20130101; H01L 2224/97
20130101; H01L 2924/01005 20130101; H01L 2924/15153 20130101; H01L
2924/19105 20130101; H01L 2224/16 20130101; H01L 23/552 20130101;
H01L 2224/05573 20130101; H01L 2924/19042 20130101; H01L 2924/09701
20130101; H01L 2924/181 20130101; H01L 2224/0554 20130101; H01L
2924/01033 20130101; H01L 2924/01074 20130101; H01L 2924/19043
20130101; H01L 2924/3025 20130101 |
Class at
Publication: |
361/728 ;
29/834 |
International
Class: |
H05K 7/00 20060101
H05K007/00; H05K 3/30 20060101 H05K003/30 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2005 |
JP |
2005-067714 |
Claims
1. An electronic component module comprising: a circuit board
having a cavity in one principal surface thereof; a first
semiconductor device accommodated within the cavity, a second
semiconductor device disposed on the one principal surface of the
circuit board so as to cover the first semiconductor device in plan
view, and a resin material disposed to cover at least a side
surface of the second semiconductor device.
2. The electronic component module according to claim 1, wherein
the resin material fills the cavity and covers the first
semiconductor device.
3. The electronic component module according to claim 1, wherein
the resin material fills a space between an upper surface of the
first semiconductor device and a lower surface of the second
semiconductor device.
4. The electronic component module according to claim 2, wherein
the second semiconductor device covers an opening area of the
cavity in plan view, and wherein a gap is provided between a lower
surface of the second semiconductor device and an upper surface of
the circuit board, the gap having a predetermined width.
5. The electronic component module according to claim 4, wherein
the width of the gap varies in accordance with a thickness and/or a
shape of an electrode that connects the second semiconductor device
and the circuit board.
6. The electronic component module according to claim 4, wherein
the width of the gap varies in accordance with a thickness of a
conductive bonding material that connects the second semiconductor
device and the circuit board.
7. The electronic component module according to claim 2, wherein
the second semiconductor device partially covers an opening area of
the cavity.
8. The electronic component module according to claim 7, wherein
the opening area of the cavity has a plurality of exposed sections
that are not covered by the second semiconductor device.
9. The electronic component module according to claim 1, wherein
the cavity has a shoulder section on which the second semiconductor
device disposed.
10. A method for manufacturing an electronic component module,
comprising: preparing a master board having a plurality of circuit
board areas, each circuit board area having a cavity in an upper
surface thereof; placing first semiconductor devices within the
cavities; disposing second semiconductor devices on the circuit
board areas, each second semiconductor device being disposed to
cover the corresponding first semiconductor device and an opening
area of the corresponding cavity and to have a gap to keep a
predetermined distance between a lower surface of the second
semiconductor device and the upper surface of the corresponding
circuit board area; applying a resin paste onto an upper surface of
the master board to cover both the first semiconductor devices and
the second semiconductor devices with the resin paste; and cutting
the master board along the circuit board areas to divide the master
board into a plurality of separate pieces.
11. The method for manufacturing the electronic component module
according to claim 10, wherein the width of the gaps varies in
accordance with a thickness and/or a shape of electrodes that
connect the second semiconductor devices and circuit boards.
12. The method for manufacturing the electronic component module
according to claim 10, wherein the width of the gaps varies in
accordance with a thickness of a conductive bonding material that
connects the second semiconductor devices and circuit boards.
13. A method for manufacturing an electronic component module,
comprising: preparing a master board having a plurality of circuit
board areas, each circuit board area having a cavity in an upper
surface thereof; placing first semiconductor devices within the
cavities; disposing second semiconductor devices on the upper
surfaces of the circuit board areas, each second semiconductor
device being disposed to cover the corresponding first
semiconductor device and to expose at least a part of an opening
area of the corresponding cavity; applying a resin paste onto an
upper surface of the master board to cover both the corresponding
first semiconductor device and the corresponding second
semiconductor device with the resin paste; and cutting the master
board along the circuit board areas to divide the master board into
a plurality of separate pieces.
14. The method for manufacturing the electronic component module
according to claim 13, wherein the opening area of each cavity
comprises a plurality of exposed sections.
15. The electronic component module according to claim 1, wherein
the resin material is formed entirely over the one principal
surface of the circuit board.
16. The electronic component module according to claim 15, wherein
a side surface of the resin material formed over the one principal
surface and a side surface of the circuit board are substantially
in flush with each other.
17. The electronic component module according to claim 1, wherein
the first semiconductor device comprises an RFIC, and the second
semiconductor device comprises a control IC.
18. The electronic component module according to claim 1, wherein
an upper surface of the resin material is covered with a shield
resin member.
19. The electronic component module according to claim 18, wherein
the shield resin member is adhered to an upper surface of the
second semiconductor device.
20. The method for manufacturing the electronic component module
according to claim 10, wherein the resin paste is applied under
reduced pressure.
21. The method for manufacturing the electronic component module
according to claim 13, wherein the resin paste is applied under
reduced pressure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35 U.S.C.
.sctn.120 to PCT Application No. PCT/JP2006/304736, filed on Mar.
10, 2006, entitled "ELECTRONIC COMPONENT MODULE AND METHOD FOR
MANUFACTURING SAME." The contents of this application are
incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to an electronic component
module having electronic component devices mounted on a circuit
board. An electronic component module is applicable to electronic
apparatuses of various purposes, such as a GPS (global positioning
system) module, a W-LAN (wireless LAN) module, a tuner module, and
a clock module.
[0004] 2. Related Art
[0005] In recent years, electronic component modules that have a
plurality of electronic component devices, such as semiconductor
devices, mounted on circuit boards are rapidly becoming common.
[0006] FIG. 14 shows a known example of an electronic component
module that includes a first semiconductor device 10 (such as a
control IC), a second semiconductor device 11 (such as an RF (radio
frequency) IC), and a plurality of passive components 13 and 14.
The semiconductor devices 10 and 11 and the passive components 13
and 14 are arranged side-by-side on a circuit board 1a, and are
covered with a metallic shield casing 15.
[0007] Japanese Unexamined Patent Application Publication No.
2003-204013 is published as a related art. The contents of this
publication are incorporated by reference in their entity.
[0008] However, in the electronic component module of the known
art, since the first and second semiconductor devices 10 and 11 are
arranged side-by-side on the circuit board 1a, the circuit board 1a
requires a space for mounting the first and second semiconductor
devices 10 and 11. This causes the circuit board 1a to be large in
size, thus unfavorably leading to size increase in the entire
structure of the electronic component module.
[0009] In addition, in the case where the electronic component
module is provided with the shield casing 15, the assembly process
of the electronic component module becomes complicated since
positioning and soldering between the shield casing 15 and the
circuit board 1a, for example, are necessary. Moreover, if the
electronic component module is to be manufactured by a technique in
which multiple electronic component modules are to be obtained from
a large board having a plurality of circuit board areas, the shield
casing as described above must be attached to each one of the
circuit boards. This significantly lowers the productivity.
[0010] An object of the present invention is to provide an
electronic component module that is compact and allows for high
productivity, and a method for manufacturing the same.
SUMMARY OF THE INVENTION
[0011] According to one aspect of the invention, an electronic
component module comprises a circuit board having a cavity in one
principal surface thereof. The electronic component module also
comprises a first semiconductor device accommodated within the
cavity and a second semiconductor device disposed on the one
principal surface of the circuit board so as to cover the first
semiconductor device in plan view. The electronic component module
further comprises a resin material disposed to cover at least a
side surface of the second semiconductor device.
[0012] According to another aspect of the invention, a first method
for manufacturing an electronic component module comprises
preparing a master board having a plurality of circuit board areas.
Each of the circuit board areas has a cavity in an upper surface
thereof. The first method further comprises placing first
semiconductor devices within the cavities and disposing second
semiconductor devices on the circuit board areas. Each of the
second semiconductor devices is disposed so as to cover the
corresponding first semiconductor device and an opening area of the
corresponding cavity and so as to have a gap to keep a
predetermined distance between a lower surface of the second
semiconductor device and the upper surface of the corresponding
circuit board area. The first method further comprises applying a
resin paste onto an upper surface of the master board to cover both
the first semiconductor devices and the second semiconductor
devices with the resin paste. The first method further comprises
cutting the master board along the circuit board areas to divide
the master board into a plurality of separate pieces.
[0013] According to another aspect invention, a second method for
manufacturing an electronic component module comprises preparing a
master board having a plurality of circuit board areas. Each of the
circuit board areas has a cavity in an upper surface thereof. The
second method further comprises placing first semiconductor devices
within the cavities and disposing second semiconductor devices on
the upper surfaces of the circuit board areas. Each of the second
semiconductor devices is disposed so as to cover the corresponding
first semiconductor device and so as to expose at least a part of
an opening area of the corresponding cavity. The second method
further comprises applying a resin paste onto an upper surface of
the master board to cover both the corresponding first
semiconductor device and the corresponding second semiconductor
device with the resin paste. The second method further comprises
cutting the master board along the circuit board areas to divide
the master board into a plurality of separate pieces.
[0014] The above features and other features, characteristics, and
advantages of the present invention will become more apparent from
the following description of embodiments with reference to the
attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an external perspective view of an electronic
component module according to the first embodiment of the present
invention, with a resin material omitted therefrom.
[0016] FIG. 2 is an exploded perspective view of the electronic
component module.
[0017] FIG. 3 is a plan view of the electronic component
module.
[0018] FIG. 4 is a cross-sectional view taken along line A-A and
illustrates a state where the electronic component module is filled
with a resin material.
[0019] FIG. 5 is a cross-sectional view taken along line B-B and
illustrates a state where the electronic component module is filled
with the resin material.
[0020] FIG. 6 is a side view of the electronic component module, as
viewed from a direction indicated by reference character C.
[0021] FIG. 7 is a cross-sectional view of a first semiconductor
device.
[0022] FIG. 8 is a cross-sectional view of an electronic component
module according to the second embodiment of the present
invention.
[0023] FIG. 9 is a plan view of an electronic component module
according to the third embodiment of the present invention, with a
resin material omitted therefrom.
[0024] FIG. 10 illustrates a step included in a method for
manufacturing the electronic component module according to the
fourth embodiment of the present invention.
[0025] FIG. 11 illustrates another step included in the method for
manufacturing the electronic component module according to the
fourth embodiment of the present invention.
[0026] FIG. 12 illustrates another step included in the method for
manufacturing the electronic component module according to the
fourth embodiment of the present invention.
[0027] FIG. 13 illustrates another step included in the method for
manufacturing the electronic component module according to the
fourth embodiment of the present invention.
[0028] FIG. 14 is a cross-sectional view of an electronic component
module of known art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] An electronic component module according to an embodiment of
the present invention will be described in detail below with
reference to the drawings.
[0030] The first embodiment will be described with a communication
high-frequency module as an example, which includes an RFIC and a
control IC respectively as first and second semiconductor
devices.
[0031] FIG. 1 is a perspective view of the electronic component
module (with a resin material omitted therefrom) according to an
embodiment of the present invention. FIG. 2 is an exploded
perspective view of the electronic component module illustrated in
FIG. 1.
[0032] FIG. 3 is a top view of the electronic component module.
FIG. 4 is a cross-sectional view of the electronic component
module, taken along line A-A in FIG. 3. FIG. 5 is a cross-sectional
view of the electronic component module, taken along line B-B in
FIG. 3. FIG. 6 is a side view of the electronic component module,
as viewed from a direction indicated by reference character C.
[0033] The electronic component module includes a circuit board 1
having a cavity 2, a first semiconductor device 10 and a second
semiconductor device 11 mounted on the circuit board 1, and a resin
material 4 covering the second semiconductor device 11.
[0034] The circuit board 1 has the shape of a substantially
rectangular prism, and has the cavity 2 in one principal surface
thereof (i.e. upper surface in the drawings). The circuit board 1
is formed by stacking a plurality of insulator layers one on top of
another, which are composed of a ceramic material, such as a
glass-ceramic material and an alumina ceramic material. Each of the
insulator layers is given a thickness of, for example, 50 .mu.m to
300 .mu.m. Although the number of the stacked insulator layers may
be any, the number is set to, for example, five to fifteen
layers.
[0035] The circuit board 1 is fabricated in the following manner.
First, ceramic green sheets are obtained by mixing an appropriate
organic solvent with ceramic powder of, for example, a
glass-ceramic material. A conductive paste, which is to become
circuits and connection pads, is applied onto a surface of each
ceramic green sheet by, for example, a commonly known
screen-printing technique. The ceramic green sheets with the
conductive paste thereon are stacked one on top of another and
pressed. Finally, the ceramic green sheets are fired at high
temperature.
[0036] As illustrated in FIGS. 4 and 5 in cross section, the
circuit board 1 has an internal conductor 16 and a via-hole
conductor 17 formed therein. The internal conductor 16 and the
via-hole conductor 17 constitute a predetermined circuit.
[0037] The lower surface of the circuit board 1 is provided with
external terminals 3, and is connected to a main board 18 through
these external terminals 3. The upper surface of the circuit board
1 is provided with electrode pads 5 and a surface conductive
pattern (not shown).
[0038] The internal conductor, the external terminals 3, and the
electrode pads 5 are made of a material mainly composed of metal,
such as Ag, Cu, W, and Mo, and are formed by, for example, applying
a conductive paste containing Ag powder, borosilicate low-melting
glass frit, an organic binder such as ethyl cellulose, and an
organic solvent onto the ceramic green sheets corresponding to the
insulator layers of the circuit board 1 by a commonly known
screen-printing technique, and then performing a firing step.
[0039] The cavity 2 provided in the circuit board 1 is a recess
having a rectangular opening and accommodates the first
semiconductor device 10.
[0040] The depth from the plane of the opening to the bottom
surface of the cavity 2 is set such that, for example, the upper
surface of the first semiconductor device 10 to be accommodated
therein is not located above the upper surface of the circuit board
1.
[0041] The first semiconductor device 10 accommodated in the cavity
2 has a first circuit of, for example, Al formed on a surface of a
semiconductor device substrate composed of, for example, Si or
GaAs. This first circuit constitutes an amplifier circuit and an
oscillator circuit.
[0042] With the surface having the first circuit set as the lower
surface, the first semiconductor device 10 is flip-chip mounted on
the bottom surface of the cavity 2. In other words, connection
terminals 6 provided on the lower surface and electrode pads 5
provided on the bottom surface of the cavity 2 are electrically and
mechanically bonded to each other with a conductive bonding
material 7 such as solder.
[0043] Similar to the first semiconductor device 10 described
above, the second semiconductor device 11 has a second circuit of,
for example, Al formed on a surface of a semiconductor device
substrate composed of, for example, Si or GaAs. This second circuit
constitutes, for example, a communication control circuit.
[0044] With the surface having the second circuit set as the lower
surface, the second semiconductor device 11 is disposed such that
connection terminals 6 provided on this lower surface and electrode
pads 5 provided on the upper surface of the circuit board 1 are
electrically and mechanically bonded to each other with the
conductive bonding material 7 such as solder.
[0045] In this embodiment of the present invention, the second
semiconductor device 11 is disposed on the upper surface of the
circuit board 1 in a state such that the second semiconductor
device 11 is directly disposed above the first semiconductor device
10 so as to cover the first semiconductor device 10 in plan
view.
[0046] Comparing the planar dimensions of the first semiconductor
device 10 with the planar dimensions of the second semiconductor
device 11, the second semiconductor device has larger planar
dimensions. Furthermore, the second semiconductor device 11 and the
opening area of the cavity 2 have substantially the same planar
dimensions.
[0047] In FIG. 3, the solid line indicates the position of the
second semiconductor device 11, the dash line indicates the opening
area of the cavity 2, and the dot-dash line indicates the position
of the first semiconductor device 10.
[0048] Even when the planar dimensions of the second semiconductor
device 11 and the planar dimensions of the opening area of the
cavity 2 are substantially the same as in this manner, the use of
outwardly extending lead-type connection terminals as the
connection terminals 6 for the second semiconductor device 11
allows the second semiconductor device 11 to be disposed on the
upper surface of the circuit board 1. The same applies to a case
where the planar dimensions of the second semiconductor device 11
are slightly smaller than the planar dimensions of the cavity
2.
[0049] As described above, the first semiconductor device 10 is
accommodated within the cavity 2 provided at the upper surface of
the circuit board 1, and the second semiconductor device 11 is
disposed above the upper surface of the circuit board 1 so as to
overlie the first semiconductor device 10. Thus, a mount area for
the second semiconductor device 11 on the upper surface of the
circuit board 1 can be omitted, whereby the circuit board 1 can be
made compact. This allows for size reduction in the entire
structure of the electronic component module. In addition, because
the first semiconductor device 10, the second semiconductor device
11, and various components 12, 13, and 14 can all be mounted on one
principal surface, the production efficiency is remarkably
high.
[0050] Especially in the case where an RFIC and a control IC are to
be used as the first and second semiconductor devices, it is
preferable that the RFIC be accommodated within the cavity 2 and
that the control IC be disposed so as to overlie the RFIC.
[0051] This is due to the fact that, by placing an RFIC that is
susceptible to noise, such as electromagnetic waves, within a
cavity and having an upper surface thereof be covered with a
control IC, an undesired external effect of electromagnetic waves
on the RFIC can be suppressed.
[0052] Referring to FIG. 7, a conductive line of the first circuit
formed on the lower surface of the first semiconductor device 10,
which is maintained at a reference potential, is electrically
connected to a conductive pattern 10a provided in the upper portion
of the first semiconductor device 10. Specifically, the conductive
line and the conductive pattern 10a are electrically connected to
each other inside the semiconductor device substrate. Thus, the
upper surface of the first semiconductor device 10 can be
maintained at a reference potential. Consequently, electromagnetic
interference between the first semiconductor device 10 and the
second semiconductor device 11 can be suppressed more
effectively.
[0053] In this case, the term "reference potential" refers to a
potential that a conductor connected to ground has, and generally
refers to a ground potential (a ground potential may be zero volts
or may not be zero volts).
[0054] In addition to the second semiconductor device 11, the upper
surface of the circuit board 1 has components mounted thereon, such
as a SAW filter 12, a crystal oscillator 13, and a chip electronic
component 14 at predetermined positions. A chip electronic
component 14 is basically an RF electronic component, such as a
capacitor, a resistor, an inductor, a balun, and a diode.
[0055] The resin material 4 is provided on the upper surface side
of the circuit board 1 so as to cover the second semiconductor
device 11, the SAW filter 12, the crystal oscillator 13, and the
chip electronic component 14.
[0056] The resin material 4 is composed of resin such as epoxy
resin and reinforces the bonding strength among the second
semiconductor device 11, the SAW filter 12, the crystal oscillator
13, and the chip electronic component 14.
[0057] In the present invention, the resin material 4 does not
necessarily have to completely cover the components mounted on the
circuit board, namely, the second semiconductor device 11, the SAW
filter 12, the crystal oscillator 13, and the chip electronic
component 14.
[0058] The resin material 4 may at least partially covers these
mounted components. For example, referring to FIGS. 4 and 5, in
this embodiment, the resin material 4 covers the side surfaces of
the second semiconductor device 11 but does not cover the upper
surface thereof. The upper surface of the second semiconductor
device 11 is directly in contact with a shield resin layer 9, which
will be described below.
[0059] In this embodiment of the present invention, the resin
material 4 also fills the cavity 2 so as to cover the first
semiconductor device 10.
[0060] Accordingly, the bonding strength of the first semiconductor
device 10 to the circuit board 1 can be reinforced.
[0061] In addition, because the resin material 4 fills a space 19
between the upper surface of the first semiconductor device 10 and
the lower surface of the second semiconductor device 11, the
bonding strength of the second semiconductor device 11 can also be
reinforced.
[0062] Referring to FIG. 6, the second semiconductor device 11 is
preferably disposed above the upper surface of the circuit board 1
such that a gap 8 having a predetermined width G is formed between
opposing areas of the lower surface of the second semiconductor
device 11 and the upper surface of the circuit board 1.
[0063] With this gap 8, when resin paste constituting the resin
material 4 is to be filled into the cavity 2, the resin paste for
covering the first semiconductor device 10 can flow into the cavity
through the gap 8 even after the mounting of the second
semiconductor device 11 has been completed. Accordingly, in the
manufacturing process, the resin material 4 covering both the first
and second semiconductor devices 10 and 11 can be formed in a
single step.
[0064] Here, the width G of the gap 8 between the opposing areas of
the lower surface of the second semiconductor device 11 and the
upper surface of the circuit board 1 is a distance between the
lower surface of the second semiconductor device 11 and the upper
surface of the circuit board 1, as illustrated FIGS. 4 and 5.
[0065] The width G may be set to, for example, 100 to 200 .mu.m so
as to allow a precursor of the resin material 4 to flow.
[0066] To provide the gap 8, the following one of or both of the
techniques (1) and (2) may be applied.
[0067] (1) The connection terminals 6 provided at the lower surface
of the second semiconductor device 11 are slightly bent
downward.
[0068] (2) The electrode pads 5 and/or the conductive bonding
material 7 used for the mounting of the second semiconductor device
11 is/are formed relatively thickly.
[0069] As illustrated in FIGS. 4 and 5, in this embodiment of the
present invention, the upper surface of the resin material 4 has a
shield resin member 9 formed thereon. The shield resin member 9 is
made of a resin material, such as epoxy resin, having metallic
powder of, for example, Ag, Al, Ni, or Fe dispersed therein. The
shield resin member 9 covers entirely the upper surface of the
resin material 4 and is in direct contact with the upper surface of
the second semiconductor device 11 without the resin material 4
interposed therebetween.
[0070] Accordingly, with the shield resin member 9 directly
covering the upper surface of the second semiconductor device 11,
penetration of undesired electromagnetic waves into the second
circuit in the second semiconductor device 11 can be suppressed,
and moreover, penetration of undesired electromagnetic waves into
the circuit provided inside the circuit board 1 can also be
suppressed. This allows the electronic component module to operate
stably.
[0071] In addition, since the shield resin member 9 has high
thermal conductivity due to the dispersal of metallic powder, heat
generated at the second semiconductor device 11 can be conducted
readily from the upper surface of the second semiconductor device
11 to the circuit board 1 or to the atmosphere. This is
advantageous in that the second semiconductor device 11 can operate
more stably.
[0072] An electronic component module according to second
embodiment of the present invention will be described below.
[0073] FIG. 8 is a cross-sectional view illustrating an electronic
component module according to the second embodiment of the present
invention.
[0074] The electronic component module illustrated in FIG. 8
differs from the electronic component module illustrated in FIGS. 1
to 6 in view of the shape of the cavity 2 and the location of the
second semiconductor device 11. Specifically, the cavity 2 has a
shoulder section 2a. The electrode pads 5 provided on this shoulder
section 2a and the connection terminals 6 provided on the lower
surface of the second semiconductor device 11 are electrically and
mechanically connected to each other with the conductive bonding
material 7.
[0075] By providing the cavity 2 with the shoulder section 2aon
which the second semiconductor device 11 is disposed, the
electronic component module can be made even more compact and have
lower profile. In addition, the shoulder section 2a can be
advantageously used as a positioning reference during the mounting
process of the second semiconductor device 11.
[0076] FIG. 9 is a top view of an electronic component module
according to third embodiment of the present invention.
[0077] In the electronic component module illustrated in FIG. 9, at
least a part of the opening area of the cavity 2 is located outside
of the second semiconductor device 11 in plan view. Thus, the
opening area of the cavity has exposed sections 23. Each of the
exposed sections 23 may be given a width H of, for example, 100 to
200 .mu.m.
[0078] Through these exposed sections 23, the resin material 4 can
flow into the cavity 2, whereby the resin material 4 covering both
the first and second semiconductor devices can be formed in one
step. As illustrated in FIG. 9, it is preferable that two or more
exposed sections 23 be provided.
[0079] A method for manufacturing the electronic component module
according to fourth embodiment of the present invention will now be
described with reference to FIGS. 10 to 13.
(Step A)
[0080] First, as illustrated in FIG. 10, a master board 20 having a
plurality of circuit board areas 22 arranged in a matrix is
prepared. Each circuit board area 22 has a cavity 2 in the upper
surface thereof.
[0081] The master board 20 is formed of multiple layers of green
sheets composed of a ceramic material, such as a glass-ceramic
material and an alumina ceramic material. In each of the board
areas of the master board 20, the upper surface thereof is provided
with electrode pads 5 and a surface circuit pattern, the inside
thereof is provided with a conductive pattern and a via-hole
conductor, and the lower surface thereof is provided with external
terminals.
[0082] The master board 20 is fabricated in the following manner.
For example, ceramic green sheets are first obtained by mixing an
appropriate organic solvent with ceramic powder of, for example, an
alumina ceramic material. A conductive paste, which is to become
electrode pads, external terminals 11, and a conductive bonding
material 7, is printed and applied onto a surface of each ceramic
green sheet. The ceramic green sheets with the conductive paste
thereon are stacked one on top of another and pressed.
Subsequently, the ceramic green sheets are fired at high
temperature. In this case, by using a commonly known punching
technique, for example, through holes are provided in the ceramic
green sheets corresponding to the layers where the cavities 2 are
to be formed, and a firing step is subsequently performed.
(Step B)
[0083] Subsequently, referring to FIG. 11, first semiconductor
devices 10 are placed inside the cavities. Then, second
semiconductor devices 11 are mounted onto the corresponding circuit
board areas 22 so as to cover the first semiconductor devices 10
and the opening areas of the cavities 2. In this case, a gap 8 (see
FIG. 6) having a predetermined width G is formed between the lower
surface of each second semiconductor device 11 and the upper
surface of the corresponding circuit board area 22. In addition to
the second semiconductor device 11, each of the circuit board areas
on the upper surface of the master board 20 has chip components
disposed thereon, although not shown, such as a SAW filter, a
crystal oscillator, and a capacitor at predetermined positions.
(Step C)
[0084] Subsequently, referring to FIG. 12, a resin paste 21 is
applied onto the upper surface of the master board 20. In this
case, the resin paste 21 flows into the cavities through the gaps
8. Thus, the resin paste 21 covers the second semiconductor devices
11, and moreover, the resin paste 21 fills the cavities 2.
Consequently, the first semiconductor devices 10 and the second
semiconductor devices 11 can be almost concurrently covered with
the resin paste 21.
[0085] When a resin paste is to be applied, a jig for reducing
pressure is preferably set so that the resin paste 21 can flow into
the cavities 2 (this application technique is called "vacuum
printing"). Such a jig may be a type that is disposed only on the
upper side or the lower side of the circuit board areas 22 or may
be a type that entirely houses the master board 20 onto which the
resin paste 21 is to be applied.
[0086] If a jig that entirely houses the master board 20 is used to
form the resin paste 21 by vacuum printing, the master board is
fitted to a frame member in which the master board 20 can be fitted
horizontally, and is set on a base. The pressure is reduced until
reaching a predetermined degree of vacuum. Subsequently, a
precursor of the resin paste 21 is printed and applied onto the one
principal surface of the master board 20. In this case, since the
master board 20 is entirely housed in the jig that maintains the
pressure at the predetermined degree of vacuum, the precursor of
the resin paste 21 supplied from the side of the one principal
surface flows into the cavities 2 through the gaps 8 or the gaps
19. By allowing the resin paste 21 to cure, the resin paste 21 can
cover both the first semiconductor devices 10 and the second
semiconductor devices 11 together.
[0087] As the resin paste 21, a mixture of thermosetting resin,
such as epoxy resin, and a hardener, a hardening accelerator, or
other appropriate inorganic fillers where necessary may be
used.
[0088] When a typical resin paste for sealing electronic components
is used, such as a resin paste having a viscosity of about 30 to 80
Pas, the gaps 8 and the gaps 19 are preferably given a width of 100
to 200 .mu.m, and the degree of vacuum during printing is
preferably set at 80 to 130 Pa. With these set ranges, the resin
paste 21 can fill the gaps 8, the gaps 19, and the cavities 2 in a
good state with fewer voids.
(Step D)
[0089] Referring to FIG. 13, the master board 20 is cut along the
circuit board areas 22 so as to be divided into a plurality of
separate pieces.
[0090] The cutting of the master board 20 and the resin material 4
is performed by, for example, cutting the master board 20 and the
resin material 4 almost concurrently from the side of the master
board 20 using a dicer, a laser, or the like. Thus, a plurality of
electronic component modules can be obtained at once. The cutting
direction may be appropriately determined on the basis of the
relationships among the cutting means and the materials used for
the master board 20 and the resin material 4. Instead of performing
the cutting from the side of the master board 20 as mentioned
above, the cutting may alternatively be performed from the side of
the resin paste 21.
[0091] As an alternative to the above-described step B, each of the
second semiconductor devices 11 may be set on the upper surface of
the corresponding circuit board area 22 so as to overlie the
corresponding first semiconductor device 10 and to allow the
opening area of the corresponding cavity 2 to be partially exposed
in plan view (see FIG. 9). In that case, in the subsequent step C,
the resin paste 21 is applied onto the upper surface of the master
board 20, and the resin paste 21 is allowed to flow into the
cavities through the exposed sections of the opening areas of the
cavities. Consequently, the first semiconductor devices 10 and the
second semiconductor devices 11 can be almost concurrently covered
with the resin paste 21.
[0092] According to the above-described manufacturing method, the
assembly process of the electronic devices is significantly
simplified, thereby allowing for improved productivity of the
electronic component modules.
[0093] According to the electronic component module, the first
semiconductor device is accommodated within the cavity provided in
an upper surface of the circuit board, and the second semiconductor
device is disposed on the upper surface of the circuit board so as
to cover the first semiconductor device. With this configuration,
the mount areas of the first and second semiconductor devices on
the upper surface of the circuit board can be reduced, whereby the
circuit board can be made compact. Accordingly, this allows for
size reduction in the entire structure of the electronic component
module.
[0094] In addition, because the second semiconductor device is
covered with the resin material, the assembly process is not
complicated as in the case where a shield casing is provided. The
resin material can easily protect the second semiconductor device
as well as reinforcing the bonding strength of the second
semiconductor device.
[0095] Furthermore, by covering the first semiconductor device with
a resin material, the bonding strength of the first semiconductor
device can be reinforced.
[0096] In particular, an upper surface of the first semiconductor
device and a lower surface of the second semiconductor device may
have a space therebetween, and a resin material may fill this
space. With this configuration, the bonding strength of the second
semiconductor device can be reinforced.
[0097] Furthermore, the second semiconductor device may be mounted
in a state such that the lower surface of the second semiconductor
device and the upper surface of the circuit board have a gap formed
therebetween. With this configuration, during the manufacturing
process, the resin material can flow into the cavity through the
gap between the lower surface of the second semiconductor device
and the upper surface of the circuit board even after the mounting
of the second semiconductor device has been completed Accordingly,
the resin material covering both the first and second semiconductor
devices can be formed.
[0098] Furthermore, in plan view of the upper surface of the
circuit board, the second semiconductor device may partially cover
an opening area of the cavity so that a remaining section of the
opening area of the cavity is exposed. Thus, the resin material can
flow into the cavity through the exposed section of the opening
area of the cavity, whereby the resin material covering both the
first and second semiconductor devices can be formed.
[0099] By providing a plurality of the exposed sections, the resin
material can flow into the cavity more readily.
[0100] Furthermore, in the electronic component module, the cavity
may be provided with a shoulder section, and the second
semiconductor device may be disposed above the shoulder section.
This allows the electronic component module to have lower profile,
whereby the entire structure thereof can be reduced in size.
[0101] In a method for manufacturing the electronic component
module, the second semiconductor devices are disposed on circuit
board areas, each second semiconductor device being disposed so as
to cover the corresponding first semiconductor device and the
opening area of the corresponding cavity and so as to have a gap to
keep a predetermined distance between the lower surface of the
second semiconductor device and the upper surface of the
corresponding circuit board area. Thus, by subsequently applying a
resin paste onto an upper surface of a master board, the resin
paste can flow into the cavities through the gaps.
[0102] Consequently, a resin material can be applied both onto the
upper surfaces of the board areas and into the cavities in the
circuit board areas, thereby allowing for improved productivity of
the electronic component modules.
[0103] In another method for manufacturing the electronic component
module, the second semiconductor devices are disposed on upper
surfaces of circuit board areas, each second semiconductor device
being disposed so as to cover the corresponding first semiconductor
device and to expose at least a part of the opening area of the
corresponding cavity. Thus, by subsequently applying a resin paste
onto an upper surface of a master board, the resin paste can flow
into each cavity through an exposed section of the opening area of
the cavity. Consequently, a resin material can be applied both onto
the upper surfaces of the board areas and into the cavities in the
circuit board areas, thereby allowing for improved productivity of
the electronic component modules.
[0104] The present invention is not limited to the above
embodiments, and various changes and modifications are permissible
without departing from the scope of the invention.
[0105] For example, in the electronic component module according to
each of the above embodiments of the present invention, the
connection terminals 6 provided at the lower surfaces of the first
and second semiconductor devices and the electrode pads 5 provided
on the bottom surface of the cavity or on the upper surface of the
circuit board 1 are connected to each other with a conductive
bonding material. Alternatively, connection terminals provided at
the upper surfaces of first and second semiconductor devices may be
connected to the electrode pads 5 by wire bonding.
* * * * *